The invention relates in general to an apparatus and method for testing condoms, and in particular to an apparatus and method for testing condoms as barriers to virus penetration.
The use of contraceptive condoms to prevent the transmission of disease during sexual intercourse has attained new urgency since acquired immune deficiency syndrome (AIDS) has become known. This has raised important questions as to the effectiveness of various condom materials as barriers to viruses, including the human immunodeficiency virus-1 (HIV-1) which is considered the causative agent of AIDS. One of the factors affecting the overall ability of condoms to control the transmission of AIDS and other sexually transmitted diseases is the integrity of the barrier material.
Retta et al. ("Test Method for Evaluating the Permeability of Intact Prophylactics to Viral-Size Microspheres Under Simulated Physiologic Conditions", Sexually Transmitted Diseases, April-June 1991, Vol. 18, No. 2) disclose a test method for evaluating the barrier effectiveness of a condom subjected to simulated physiologic conditions. One of the problems with the Retta method arises from the use, as a substitute for a virus, of a fluorescent polystyrene microsphere, which is a biologically irrelevant and unstable particle. The polystyrene microspheres often break into pieces during the test. Therefore, measured data concerning the size of particles penetrating the condom is practically meaningless. Additionally, it is unclear how the measured barrier effectiveness of a condom to a polystyrene microsphere or pieces of a microsphere correlates with the barrier effectiveness of a condom to a virus.
Another problem with the Retta method is its complexity and the expense of the test apparatus for implementing it. The Retta method uses specially designed components which are not commercially available. Furthermore, in a biologic test system, after a condom is tested, the testing system must be sterilized or a new testing system provided before another condom is tested. In the Retta method, the test components are relatively expensive and therefore uneconomical to replace after each test. Also, the materials used for the components of the Retta test method are not readily sterilizable. Therefore, the Retta method is not adaptable to testing condoms for viral penetrability using a virus in the test method.
Lytle et al. ("Virus Leakage Through Natural Membrane Condoms", Sexually Transmitted Diseases, April-June 1990, Vol. 17, No.2) disclose a method for determining virus leakage through natural membrane condoms. In this method, there are several problems. First, the method does not test the entire useable condom surface. Second, the method does not employ physiological pressure. Therefore, the results are not useable for risk assessment.
Other prior art methods using viruses do not have any control over or knowledge of the pressure, nor do they test the entire useable surface of the condom. Therefore, the results of those methods are not interpretable or useable for risk assessment.